Eloy E. Schulz

Relationship between trabecular vertebral body density and fractures: A quantitative definition of spinal osteoporosis

To evaluate the relationship between vertebral fractures and trabecular vertebral body density (TVBD), as measured by computed tomography (CT), we evaluated 110 female and 38 male patients referred consecutively to our clinic for an osteoporosis evaluation. Number of fractures per patient and TVBD was negatively correlated in both males and females (r = -.64, P less than .001 and r = -.69, P less than .001, respectively). Based on this relationship and that between percent of patients with fracture and TVBD, we devised four different approaches to calculate the fracture threshold. (1) Because the x-axis intercept of this regression line represents the TVBD value at zero fractures, this intercept can be considered the fracture threshold, which was 103 mg/cm3 for females and 132 mg/cm3 for males. (2) Breakpoint analysis of the relationship between the number of vertebral fractures per patient v TVBD gave a fracture threshold value of 98 mg/cm3 for females, but for males we were unable to compute a threshold value because of the small sample size. The percentage of patients with fractures was also negatively correlated with TVBD for males and females (r = -.98, P less than .001, and r = -.94, P less than .001, respectively). (3) the x-axis intercept of this relationship, which represents the fracture threshold, was 123 mg/cm3 for males and 101 mg/cm3 for females. (4) The fracture threshold, calculated as the mean TVBD + 2 SD for patients with fracture(s), was 120 and 92 mg/cm3 for males and females, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Fluoride therapy for osteoporosis: a review of dose response, duration of treatment, and skeletal sites of action.

SummaryOsteoporosis is a disease characterized by a reduction in bone density which predisposes to fracture after even minimal trauma. Fluoride, because it has consistently been shown to stimulate bone formation and increase trabecular bone density, has been widely studied for the treatment of osteoporosis. The article focuses on the dose response, duration of treatment, and skeletal sites of action of fluoride; we also include comments on the effect of fluoride on vertebral and appendicular fracture rates. The skeletal response to fluoride doses, ranging from 15 to 43 mg elemental fluoride per day, included a linear increase in spinal bone density at an average rate of 1.25±0.91 mg/cm3 per month. The rate of increase in spinal bone density was related to the dose of fluoride (r=0.34,P<0.03). Spinal bone density had increased above the fracture threshold in 44% of patients treated with fluoride for 32±10 months. The time required to achieve this goal was, however, influenced by the pretreatment spinal bone density and interpatient variation in response to fluoride treatment. Patients whose spinal bone density remained below the fracture threshold had lower pretreatment bone densities and/or slower rates of increase in spinal bone density (P<0.001). The osteogenic effect of fluoride was not limited to the spine. After 2 years of fluoride therapy, we found bone density in the femoral condyle (measured by QCT) to have increased by 13±2.6 mg/cm3 (n=38,P<0.001); bone density in the hip (measured by DPA) was increased by 0.0261±0.015 g/cm2 (n=55,P<0.025). The efficacy of fluoride therapy to reduce fractures is not well established. Recently, investigators from the Mayo Clinic and Henry Ford Hospital reported fluoride had no effect on the vertebral fracture rate despite a significant increase in spinal bone density, but this finding has not been supported by findings in other studies. Moreover, our preliminary analysis of over 500 fluoride-treated patients found a time-dependent decrease in vertebral fracture rate related to a corresponding increase in spinal bone density. We conclude that these data, together with the many other positive international findings related to fluoride, justify continued investigation of this potent agent for the treatment of osteoporosis.

Post-laryngectomy localization of I-131 at tracheostomy site on a total body scan.

A post-thyroidectomy, post-I-131-therapy patient had a laryngectomy and neck dissection for recurrent papillary thyroid carcinoma. A subsequent I-131 total body scan revealed persistent anterior neck activity, which disappeared upon removal of the tracheostomy tube and dressings.

Usefulness of Spect in Evaluating Osteosarcoma Metastases to the Lung

The differentiation of osteosarcoma metastases to the lung vs the ribs with bone scanning agents is not always clear. Single photon emission computed tomography is useful in such differentiation.

Cine Display Of Wall Motion Of The Heart, Using Technetium-99m Labeled Red Cells, Scintillation Camera, ECG Gate, Computer, And Video Recorder

Wall motion studies of the left ventricle are made with commercially supplied hardware and software. The patient is imaged with the scintillation camera 10 minutes after the in-jection of 20 mCi labeled red cells. The camera images are digitized and stored in com-puter memory. The computer divides the cardiac cycle into 28 segments and stores a separate image sequentially for each segment. In order to provide images of adequate statistical quality several hundred cycles are acquired and summed by the computer, each sequence of 28 images being triggered by a signal from the R wave. Three or more projections of the heart are acquired in order to demonstrate various portions of the wall tangentially. A number of case studies are displayed in real time cine on a monitor from a video recorder to demonstrate normal wall motion and various degrees of motion impairment.